Winter is coming to the ALS Ice Bucket Challenge, courtesy of George R.R. Martin.

Standing poolside, Martin responded to the challenge to have a bucket of ice water dumped on his head and/or donate to the ALS Assn.

"Winter is coming," Martin said in the video, quoting the House of Stark motto from his books and "Game of Thrones." As buckets of water were poured over his head, Martin yelped and, head down, added, "Winter came.

Writer Neil Gaiman was one of three who challenged Martin. Where Martin's video was low-res, Gaiman's is artfully choreographed. Walking along Santa Monica beach, Gaiman took off one article of clothing after another, leaving them on the arms of women dressed in black. In just his skivvies, he got doused with a bucket of ice and seawater.

A few bestselling writers have joined the fun. Stephen King challenged John Grisham, who said in his video, "I was challenged by my former friend Stephen King, who's now just a mere acquaintance." Grisham withstood his bucket of ice water with a cigar clenched between his teeth.

Other writers who've taken the challenge include Elissa Schappell ("Blueprints for Building Better Girls"), crime novelist Bill Loehfelm ("The Devil in Her Way"), and several Tor authors, including Brandon Sanderson, Alex Bledsoe, David Brin and Dan Wells.

Since the challenge went viral, the organization has raised $79.7 million, more than 30 times as much as it did during the same period last year, from July 29 to Aug. 25. Funds will support research into Amyotrophic lateral sclerosis, also known as Lou Gehrig's disease.